diff mbox series

[10/13] mm/filemap: fix readahead return types

Message ID 20210515002730.MMtwMHtp5%akpm@linux-foundation.org (mailing list archive)
State New, archived
Headers show
Series [01/13] mm/hugetlb: fix F_SEAL_FUTURE_WRITE | expand

Commit Message

Andrew Morton May 15, 2021, 12:27 a.m. UTC 
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Subject: mm/filemap: fix readahead return types

A readahead request will not allocate more memory than can be represented
by a size_t, even on systems that have HIGHMEM available.  Change the
length functions from returning an loff_t to a size_t.

Link: https://lkml.kernel.org/r/20210510201201.1558972-1-willy@infradead.org
Fixes: 32c0a6bcaa1f57 ("btrfs: add and use readahead_batch_length")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/iomap/buffered-io.c  |    4 ++--
 include/linux/pagemap.h |    6 +++---
 2 files changed, 5 insertions(+), 5 deletions(-)
diff mbox series

Patch

--- a/fs/iomap/buffered-io.c~mm-filemap-fix-readahead-return-types
+++ a/fs/iomap/buffered-io.c
@@ -394,7 +394,7 @@  void iomap_readahead(struct readahead_co
 {
 	struct inode *inode = rac->mapping->host;
 	loff_t pos = readahead_pos(rac);
-	loff_t length = readahead_length(rac);
+	size_t length = readahead_length(rac);
 	struct iomap_readpage_ctx ctx = {
 		.rac	= rac,
 	};
@@ -402,7 +402,7 @@  void iomap_readahead(struct readahead_co
 	trace_iomap_readahead(inode, readahead_count(rac));
 
 	while (length > 0) {
-		loff_t ret = iomap_apply(inode, pos, length, 0, ops,
+		ssize_t ret = iomap_apply(inode, pos, length, 0, ops,
 				&ctx, iomap_readahead_actor);
 		if (ret <= 0) {
 			WARN_ON_ONCE(ret == 0);
--- a/include/linux/pagemap.h~mm-filemap-fix-readahead-return-types
+++ a/include/linux/pagemap.h
@@ -997,9 +997,9 @@  static inline loff_t readahead_pos(struc
  * readahead_length - The number of bytes in this readahead request.
  * @rac: The readahead request.
  */
-static inline loff_t readahead_length(struct readahead_control *rac)
+static inline size_t readahead_length(struct readahead_control *rac)
 {
-	return (loff_t)rac->_nr_pages * PAGE_SIZE;
+	return rac->_nr_pages * PAGE_SIZE;
 }
 
 /**
@@ -1024,7 +1024,7 @@  static inline unsigned int readahead_cou
  * readahead_batch_length - The number of bytes in the current batch.
  * @rac: The readahead request.
  */
-static inline loff_t readahead_batch_length(struct readahead_control *rac)
+static inline size_t readahead_batch_length(struct readahead_control *rac)
 {
 	return rac->_batch_count * PAGE_SIZE;
 }